This post is part of the Mac Quick Tips Series.
When you get your shining new Mac and initially set it up, it will by default be set to have an automatic login. Meaning when the machine boots up it won’t ask for a username and password.
In this _really_ quick tip you’ll see how to setup your mac so that it will prompt you for a username and password before access is granted to use the machine.
First, go to the System Preferences and click Security.
Here you will see a screen similar to the screen shot below.

All that’s required is tick the box Disable automatic login and you’re done.
Next time you start your computer you’ll be prompted for a username and password.